1. Field of the Invention
The present invention relates to building materials on a cement-free base and more particularly to a composition for preparing artificial stone materials.
2. Description of the Related Art
Known in the art is a composition for preparing construction stone materials (SU, A, 808470), having the following formulation (mass %):
boric acid: 10-20 PA1 limestone: 70-80 PA1 water: up to 100 PA1 liquid glass: 15-25 PA1 ash: 10-30 PA1 aluminium powder: 0.003-0.005 PA1 limestone: up to 100 PA1 liquid glass: 92-95.5 PA1 dry silica: 1.5-2.4 PA1 boric acid: 3.0-6.0 PA1 cullet: 20-50 PA1 basic blast furnace slag: 50-80 PA1 soluble glass: 3-65 PA1 limestone: 1-75 PA1 aqueous solution of an acid with pH 1-4: 5-52 PA1 average density, kg/m.sup.3 : 1000-2100 PA1 ultimate compressive strength, MPa: 5.0-78.0 PA1 ultimate bending strength, MPa: 3.0-30.0 PA1 frost resistance, cycles: up to 400 PA1 average density, kg/m.sup.3 : 100-10000 PA1 ultimate compressive strength, MPa: 0.3-20.0 PA1 ultimate bending strength, MPa: 0.3-9.0 PA1 heat conductivity, W/m.multidot.K: 0.035-0.21 PA1 soluble glass: 3-40 PA1 silicate component with the content of silicon dioxide exceeding 60 mass %: 1-70 PA1 limestone: 1-70 PA1 aqueous acid solution with pH 1-4: 5-52 PA1 soluble glass: 9-15 PA1 silicate component with the content of silicon dioxide exceeding 60 mass %: 1-70 PA1 limestone: 1-70 PA1 aqueous acid solution with pH 2-4: 5-52 PA1 soluble glass: 20-40 PA1 silicate component with the content of silicon dioxide exceeding 60 mass %: 20-40 PA1 limestone: 2-10 PA1 aqueous acid solution with pH 1-3: 5-52 PA1 soluble glass: 3-5 PA1 silicate component with the content of silicon dioxide exceeding 60 mass %: 15-50 PA1 limestone: 20-60 PA1 basic blast furnace slag: 10-30 PA1 aqueous acid solution with pH 1-2: 5-52
The material prepared from such a composition has a high ultimate compressive strength, 63.0 MPa, but features an enhanced brittleness, since it has a low ultimate bending strength, 7.0 MPa. For this reason this material has a limited application.
A composition is known for preparing construction artificial stone materials (SU, A, 464560), having the following formulation (mass %):
Liquid glass, having a constant sodium silicate component/water ratio, fails to ensure high strength characteristics of the materials prepared from such a composition (ultimate compressive strength, 42.0 MPa; ultimate bending strength, 10.0 MPa; the frost resistance of the material does not exceed 100 cycles). Such a composition is poorly adaptable to the method of semi-dry pressing, since liquid glass, because of its viscosity, is difficult to mix with dry components and is liable to segregation upon prolonged storage.
A composition is known for preparing a heat insulating material (SU, A, 863575), comprising the following components (mass %):
The material prepared from this composition is characterized by a low heat conductivity (.lambda.=0.06 W/m.multidot.K) due to the average density of up to 200 kg/m.sup.3, but it has low ultimate compressive strength, 0.41 MPa, and ultimate bending strength, 0.08 MPa, which limits its application as a building heat insulating material. The coefficient of water resistance is smaller than 0.5, so that the material cannot be used in a medium with an elevated humidity.
Also known is a composition for preparing refractory stone materials (SU, A, 763280), comprising the following components (mass %):
The material prepared from this composition by sintering at a temperature of up to 750.degree. C. with an average density of 1800 kg/cm.sup.3 is characterized by the ultimate compressive strength of 21 MPa and ultimate bending strength of 2 MPa, which become appreciably reduced at a temperature above 800.degree. C., so that the application of this material, for instance, as heat-resistant blocks or high-temperature insulation for industrial units and equipment, is limited, insofar as the service temperature of these items exceeds 1000.degree. C.
The main object of the invention is to provide such a composition for preparing artificial stone materials by appropriate qualitative and quantitative selection of the components, which would ensure enhanced compressive and bending strength characteristics of said materials under different service temperature conditions, as well as a low heat conductivity thereof.